In medical testing and processing, the use of robotics may minimize exposure to, or contact with, bodily fluid samples (otherwise referred to as “specimens”) and/or may increase productivity. For example, in some automated testing and processing systems (e.g., clinical analyzers and centrifuges), sample containers (such as test tubes, sample cups, vials, and the like) may be transported to and from sample racks (sometimes referred to as “cassettes”) and to and from a testing or processing location or system.
Such transportation may be accomplished by the use of an automated mechanism, which may include a suitable robotic component (e.g., a moveable robot arm or gantry arrangement) having a moveable end effector that may have gripper fingers coupled thereto. The end effector may be moved in two or more coordinate directions (e.g., X, R, and Z). In this way, a sample container (containing a specimen to be tested or processed) may be gripped by the end effector, and then moved from one location to another in relationship to the testing or processing location or system. For example, the sample container may be moved to and from a receptacle of a sample rack.
Inaccurate calibration may result in inaccurate positioning of the end effector and may cause collisions or jams between the end effector and the sample container, and/or between the sample container being moved and the testing or processing system or sample rack. Additionally, inaccurate calibration may contribute to jarring pick and place operations of the sample container, which may contribute to unwanted spillage of specimen from the sample container. Furthermore, knowing a precise rotational orientation of the end effector fingers may allow for the manufacture of smaller sample racks, in that the fingers may be placed in a defined orientation when grasping the sample container, thereby allowing the distance between respective sample containers in the sample rack in other directions to be minimized.
Accordingly, methods, systems, and apparatus that may improve accuracy of positioning of a robotic component relative to an article, such as a sample rack, in testing and processing systems are desired. Furthermore, methods that improve accuracy of positioning of robot fingers of end effectors are also desired.